Method and a unit for producing round bales of straw or of like material with film wrapping

ABSTRACT

For various reasons it is attractive to effect a sheet or film wrapping of round bales of straw or similar material, but so far has required the use of a costly special equipment. With the invention the wrapping is effected with a simple film supply device mounted on the round bale producing baler itself, such that the bales are delivered therefrom in ready wrapped condition.

The present invention concerns a method for producing round bales ofstraw or of like material with film wrapping. It has become a widelyused practice to keep straw in the outdoors in the form of bales, inthat rows of bales are either covered by a film or are made up of balesprovided with a film wrapping for weather protection. Bales to be usedas fodder are injected with ammonia and are completely wrapped up,either individually or collectively in a kind of film tube, whichrequires a relatively expensive apparatus.

However, much of the straw is used as bedding for livestock, and it issufficient that these bales are wrapped with film around theircircumference. This may be effectuated with a perceptibly simplifiedwrapping apparatus. Moreover, it is also so that round bales for thatuse are commonly produced by use of baling presses, which are farcheaper than more industrial presses, which mostly are rented throughmachine pools and used for the production of the larger "big bales" in around or box-shaped form for ensiling or for different industrialpurposes.

More and more it is realized, that the gathering in of straw from thefield is becoming so expensive, that soon it will be more profitablejust to plough down the straw since it may no longer be burned. This isalso the case with straw for bedding, where it is decisively necessaryto minimize the gathering costs. As mentioned here, it is true thatcomparatively inexpensive baling presses and wrapping apparatuses may beused, but the combined costs for the machinery and the expendablesbelonging thereto, namely binder twine for the round baler and wrappingfilm for the wrapping apparatus, are very straining for theprofitability.

By the present invention it is realized, that these conditions may beperceivably bettered by the fact, that it has been found possible toprovide the relevant, conventional round bale presser with acomparatively uncomplicated device, which instead of winding twinearound the single finished round bale may wrap the bale up with a lengthof packing film in such a way that the film wrapping will serve both asa structural stabilization of the round bale and as the required packingof it. Thereby it is not only achieved, that the expendable constitutedby the twine may be completely avoided, but also that the use of aseparate wrapping apparatus may be abandoned entirely, because itsfunctions are taken over by the combined effect of the film supplydevice and the baling press itself.

Thereby it is achievable that the relatively simple baler may readilydeliver round bales in the shape of already stabilized and relevantlypacked items, which in this way may be placed side by side, forming amainly weatherproof row of protected single bales.

The baling presses in question works in a way, that by driving over thefield they continuously collect loose straw by means of a pick-upcylinder, which presses the straw towards a set of running, elasticallytightened belts, which yield inwardly as more straw is supplied; acontinuously supplied layer of straw will thereby be wound up againstthe action of the elastic force of the belts, which at last run in analmost closed loop around the produced round bale. Just before itreaches the desired size there is supplied a free end of a twine to theinlet, which twine in this way will be embedded between the hithertoperiphery of the bale and the straw layer succeedingly wound up on it.Following less than a further turn of the bale the hauling of the balingpress is stopped, while the said belts continue to turn the bale,whereby the bale through 10-15 revolutions is winded with twine from aspool of binder twine, in that the twine spool hereby is displacedsidewardly, so that the winding takes place from edge to edge of thebale's peripheral area. Thereafter the twine is cut off, the twine beingselfkeeping after the last several windings, and the bale is deliveredto the ground by opening the belt system.

By the invention it is realized that it will be possible to substitutethe twine supply with a supply of wrapping film according to quite thesame principle, whereby it will also be possible to leave out the twineand, not the less, the complete separate wrapping apparatus, whichnormally is necessary for the desired packing. Then it is important,that the film can be supplied in just the same simple way as the twine,and that the supply may be stopped not only in the same simple way, butin an even simpler way, in that the preferably used film is a stretchfilm quite corresponding to the well-known `domestic` film, which sticksto itself; thereby not even a single wrap around the bale is necessaryin order to finally secure a fastening of the wrapped-up material.

Normally it will apply that the film web is delivered from a film rollwhich is narrower than the width of the bale, why this roll in the sameway as the said twine spool should be able to move sidewardly during thewrapping process. Hereby it is important, though, that the wrapping upof the film can be finished with far less revolutions of the bale thanby the winding of the twine, since this means that the duration ofnecessary stops in the straw collecting process may be considerablyshortened, resulting in a corresponding increase in the collectingcapacity.

On this background the invention will also comprise a winding apparatusfor mounting both on existing round baling presses and on such presses,which originally have been provided with such a device.

The invention will be explained in more detail in the following withreference to the drawing, where

FIG. 1 is a schematic side view of a conventional baling press of arelevant type as shown just before the commencement of the rolling up ofa straw bale,

FIGS. 2 and 3 are corresponding views shown during the beginning and thefinish of a rolling up,

FIG. 4 is a corresponding view of the press during delivery of the bale,and

FIG. 5 is a schematic perspective view for illustrating the invention,and

FIG. 6 is a corresponding view of an amended embodiment.

The baling press shown in FIGS. 1-4 is well-known and shall thereforeonly be described briefly. On driving wheels 2 there is placed a frame4, which keeps a circumferential row of guide rollers for acircumferential wrapping and pressing belt 6, and a corresponding systemof parallel belts, respectively. Between lower, foremost guide rollers 8and 10 and just in front of the roller 8 there is placed a fixedpressing roller 12, which is sitting at the outside of the belt 6, anddown before this roller there is placed a rotating pick-up roller 14 forthe continuous collecting of a loose straw layer 16 from the field andfor pressing the straw therein to the area between the rollers 12 and10. The belt 6 is kept elastically suspended by control through an upperbelt tensioning and expansion system 18.

By the said pressing in of the straw the belt section between therollers 8 and 10 yields inwardly, and by moving the belt in thedirection of the arrow in FIG. 2, immediately there will initiated arolling up of the pressed in layer of straw, whereby the belt loopbetween the rollers 8 and 10 will be enlarged inwardly, while the beltis freed correspondingly from the tensioning system 18. The straw layeris compressed at the inlet over the pressing roller 12, see FIG. 3, andbesides by the elastic tensioning of the belt 6 itself.

When the desired bale size has been achieved, FIG. 3, the hauling isstopped, and after the previously mentioned winding up of the bale withtwine by which the bale is rotated 10-15 times, the finished bale isdelivered by opening the baling press as shown in a self-explaining wayon FIG. 4, after which the procedure may be recommenced.

By the present invention all of the binder twine arrangement may beomitted, since instead there may be utilized an additional equipment asindicated in FIG. 5, where this equipment is shown in a initial positionat the bottom of the right side and in a final position at the top ofthe left side. The equipment consists of a film roll 20 carried by asupporting frame 22, which is placed horizontally displaceable on asupporting rail 23 and driven by a motor 25 via a not shown threadedspindle. The rail 23 is connected movably up-and-down to the machineframe in a not shown way, as indicated by the double arrow. Thesupporting frame is hereby movable between the two said positions, whichas implied by the punctuated arrows either directly by a sloped courseor by a horizontal/vertical course.

The supporting frame 22 has an inner, downwardly projecting back plate24 having a bottom edge to which the film 19 from the roll 20 can beconveyed together with foremost, elastic holding fingers 26 pressing theunrolled film against the bottom edge of the back plate 24.

At the first time of use it is provided that the film 19 is pulled a bitbelow the bottom edge of the back plate 24, in that there is commencedwith the frame 22 in an elevated position and therefore with a piece offilm 21 hanging freely therefrom. When the first bale is about to finishwinding up, the frame 22--preferably with an automatic control--isactuated to be moved to its lowered position in the right side, wherebythe hanging film end 21 is brought in abutment against the straw flow 16and together with this is inserted over the pressing roller 12 to asqueezed position between the hitherto outside of the bale and the newlysupplied layer 16. Thereby the film end is anchored in the bale, andthen the hauling is stopped.

However, the rotation of the bale is continued by means of the drivenbelt 6, and thereby the film 19 will be pulled out for an initialwrapping up of the bale. During the further rotation the frame 22 isdisplaced tranversely, either slantingly upwards against the elevatedposition in the left side or horizontally to the left, in that theelevation to a higher final level then may happen at any time includingat the beginning or the termination of the wrapping. The wrapping upwith a few overlapping film windings may be finished by relatively fewrevolutions of the bale, e.g. only 5-8 revolutions, and the rotation isstopped when the frame 22 has reached its left, elevated position.

Now the whole of the outer surface of the bale is covered with film, andthe film 19 is suspended between the bottom edge area of the back plate24 and the inlet just below the roller 10. Hereby there is anopportunity to cut off the film somewhere in this section, so thatthereby the desired hanging film end can be created before the beginningof the next wrapping operation. This may be done with a shearing beam28, which has a movable knife 30 for shearing the film or possibly a hotwire for melt-cutting the film.

As film material there is preferably used a thin, slightly stickystretch-film of the same type as the usual "domestic film". It should beaimed at unrolling the film from the bulk roll with a perceivableresistance against the unrolling, so that a certain stretching of thefilm takes place. This is important, not the least at the finalwrapping, where the tightened film layers on the bale will produce aself-locking sticking engagement, so that automatically there isachieved a sufficient fastening of the outer end of the film.

By experiments it has appeared, that the cutting off of the film may bedone without the said special shearing, i.e. quite without use of theshearing beam 28, namely by shortly applying a brake to the unrolling ofthe film from the roll/frame 20,22. Hereby the film will be subjected toa strong tensile influence from the roller 10, which will act on thefilm in an outward direction from the inlet of the bale, so that thefilm is pulled apart close to the roller 10. Thereby the hanging filmend 21 to be used at the beginning of the next wrapping operation isformed.

In FIG. 6 there is shown an amended embodiment, where the film rollholder 22 and the film roll 20 are extending over the whole width of thebale, whereby there may be dispensed with the special supporting rail 23with driving equipment 25 belonging to it. However, the holder 22 shouldalways be supported in a vertically displaceable way with a view to theformation and the activation of the freely hanging film end for aninitial engagement with the bale, so that the film web will becomenarrower by the said stretching of the web, the film roll should have acertain excessive length as compared with the width of the bale.

The embodiment according to FIG. 6 is particularly suitable for use withnew baling presses, where an accordance between the bale width and astandard width can be made, while the embodiment according to FIG. 5 isparticularly suitable for mounting on presses, where the bale widthdeviates from the attainable standard widths of the film web material.

I claim:
 1. A method for producing round bales of straw with a filmwrapping comprising the steps of:driving a baling press over a fieldwhile operating the baling press so as to continuously collect a layerof straw, progressively roll up the layer of straw and simultaneouslycompress the straw during rolling up thereof; conveying a free end of afilm web in a manner causing the free end to be drawn into a joint facebetween an outer side of a bale being produced and a final straw layerbeing rolled on to the bale, said conveying step comprising the step oflowering a film supply roll of the web film, with the free end of thefilm web hanging down therefrom, and bring the free end of the web intoabutment with an upper surface of the straw layer, anchoring the freeend within said joint face by the free end being drawn in with saidstraw layer; subsequently terminating the intake of the straw layer androtating the bale to form a full wrapping thereof with the film web; andduring or at said full wrapping of the bale with the film web, elevatingthe film supply roll to a higher position, producing a shearing ortearing off of the film web at a level perceivably below the supply rolland creating a new hanging free end of the film web for use in wrappingof a subsequently rolled bale.
 2. Method according to claim 1, whereinsaid step of producing a shearing or tearing off of the film web isperformed by the step of braking rotation of the supply roll duringcontinued rotation of the bale.
 3. Method according to claim 1, whereinsaid film web is perceivably narrower than the bale and wherein the stepof raising and laterally displacing the film supply roll is performedduring the step of full wrapping of the bale with the film web. 4.Apparatus for producing round bales with a film wrapping having awrapping unit comprising mounting means for mounting the wrapping uniton a straw layer collecting, round baling press, a holding means forrotatably supporting a film supply roll with a free end of the filmhanging down, means for raising and lowering the holding means relativean intake area of the baling press to which the mounting means isattached, in use, between an inactive raised position and an activelowered position, and means for applying the free end of the filmagainst an upper surface of a straw layer being collected into thebaling press in said lowered position for enabling the free end of thefilm to be drawn into a joint face between an outer side of a bale beingproduced and a final straw layer being rolled on to the bale. 5.Apparatus according to claim 4, wherein said film web is perceivablynarrower than the bale to be wrapped therewith; and wherein the meansfor raising and lowering the holding means comprises means for laterallydisplacing the holding means for the film supply roll as it is raisedfrom the lowered position toward the raised position for producing fullwrapping of the bale with the narrower film web.
 6. Apparatus accordingto claim 4, further comprising means for sheering or tearing off thefilm web at a perceivable distance below the film supply roll. 7.Apparatus according to claim 4, further comprising means for brakingrotation of the film supply roll for effecting rupturing of the film webnear the intake area of the baling press in response to further rotationof the bale.
 8. A straw layer collecting, round baling press forproducing round bales having means for driving the press over a fieldand for operating the baling press so as to continuously collect a layerof straw, progressively roll up the layer of straw and simultaneouslycompressing the straw during rolling thereof, having a film wrappingunit, said wrapping unit comprising mounting means for mounting thewrapping unit on the baling press, a holding means for rotatablysupporting a film supply roll with a free end of the film hanging down,means for raising and lowering the holding means relative an intake areaof the baling press between an inactive raised position and an activelowered position, and means for applying the free end of the filmagainst an upper surface of a straw layer being collected into thebaling press in said lowered position for enabling the free end of thefilm to be drawn into a joint face between an outer side of a bale beingproduced and a final straw layer being rolled on to the bale.
 9. Balingpress according to claim 8, wherein the holding means for the film rollis perceivably narrower than the width of the bale; and wherein themeans for raising and lowering the holding means comprises means forlaterally displacing the holding means for the film supply roll as it israised from the lowered position toward the raised position forproducing full wrapping of the bale with the narrower film web. 10.Baling according to claim 8, further comprising means for shearing ortearing off the film web at a perceivable distance below the film roll.11. Baling press according to claim 8, further comprising means forbraking the rotatability of the film supply roll in order to effectrupturing of the film web near said intake area in response to furtherrotation of the bale.